Printing-ink



- ful Printing-Ink, of which the following is aa thin filmof pyroxylin is applied to the en- PATENT ()FFICE.

FRANCIS B. HALL, or, PLATTSBURG, NEW YORK.

PRINTING-INK.

SPECIFICATION forming part of Letters Application filed January 20, 1898.

Patent No. 606,542, dated June 28, 1898. Serial No. 667,323, on specimens.)

To 0055 whom it may concern:

Be'itknown that I, FRANCIS B. HALL, a citizen of the United States, and a resident of Plattsburg, in the countyof Clinton and State of New York, have invented a new and usespecification, I r

My invention has reference particularly to a composition to be used for printing postagestamps or other stamps which are not to be used more than once, and it is designed to produce a composition which while adapted in all respects for printing purposes yet is very sensitive to the action of water or other liquids-such as alcohol, ether, or the like which are employed'either for removing the canceling-mark from the stamp or, in conjunction with'other ingredients, for putting over the stamp a washable film which will receive the canceling-mark and will protect the stamp fromthe same: The latter expedient is one which is'not infrequently used to defraud the Government-as, for example, in the case of a stamped envelop the stamp is covered with a thin film of gelatin,'then velop, whose stamp is protected from the action of the pyroxylin by the previously-applied gelatinous film, and then over all is applied a film of gelatin. This film of gelatin receives the cancelingmark as well as the written address, the ink being prevented from penetrating to the paper by the underlying pyroxylin film. The receiver of the envelop. with a moist brush can remove the gelatin film, carrying with it the ink used for cancellationas well as foraddressing, and after subsequent manipulation and treatment,-which it is not necessary here to enter into the detailsof, the envelop with its stamp is readyfor another use. This is a scheme which I am informed and believe is made use of not infrequently in the case of stamped envelops, and in the case of stamps separate from the envelop the same expedient is availed of that" is to say, the stamp is covered with a thin film of gelatin or pyroxylin, or both,which receives the canceling-mark and prevents it from reaching the ink of the stamp and which can be removed and renewed as often as desired if the operation be conducted with reasonable care. It is my object to provide an inkfor the stamp which will not permit the application of any of the protecting films re ferred to without being so affected and defaced as to unfit the stamp for further'use.

To this end I make an ink or composition of matter the body of which is composed,

essentially, of saccharin matter (such as sugar) and salicylic acid. Four ounces of cold Water can hold in solution but eight ounces of sugar. The same quantity of hot-.waterwill dissolve twenty ounces of sugar. addition, however, of salicylic acid the water can be made to dissolve twenty-four ounces and evenmore of sugar and retain the same in solution at ordinary temperatures.- So, too, four ounces of water will dissolve at ordinary temperature but five grains of salicylic acid,and at atemperature of 212 Fahrenheit only about two drams of the acid; but in the presence of the sugar six or more drams of the acid can be dissolved, the sameapparently uniting with the sugar to form a new compound which is stable, of opaque snowywhite appearance, and of viscid consistency. These two ingredientsthe saccharin matter and the salicylic acidwhen dissolved in water and mixed thoroughly together form an admirable vehicle for pigment or coloringmatter, giving distinctive hues or tints. I may add to such solution a small percentage of gum-arabic or any other suitable mordant WVith thefor the purpose of setting and fixing thecomingredients may vary considerably. The best results on the whole have been obtained by me by using, say, six drams of the acid to four ounces of water, twelve ounces of sugar, and one ounce of gum-arabicthat is to say, by the use of about four and one-half per cent. of acid to the mass of other materials, estimating the latter at one hundred and thirtysix drams. So far as I have been able to ascertain the percentage of acid must not fall materially below three per cent., or, say, four drams of acid to one hundred and thirtysix-drams of the other materials mentioned. One formula which I in practice have used with excellent results is as follows: Water, by measure, four ounces; sugar, by weight,

twelve ounces; gum-arabic, by weight, one ounce; salicylic acid, by weight, five drams; eosin or other desired and suitable coloringmatter, eight ounces and six and one-half d rams; glycerin, six ounces and five drams, or as much thereof according as maybe needed to retard drying. It will be understood that these figures are not arbitrary, I have used as high as thirteen ounces, by measure, and even more of glycerin, and the percentage, by weight, of the coloring-matter can also vary. As to the main ingredients, it will be noted that the sugar is largely in excess of the water, and the salicylic acid, which renders it possible to make use of this relatively large quantity of sugar, should not for this purpose be materially less than three per cent. of the mass. I first dissolve the gumarabic in water and place the same in a suitable receptacle, preferably of transparent glass. I then add to the liquid the sugar and salicylic acid and place the said receptacle in a vessel of lukewarm water, wherein it can be heated to a temperature of 212. The mixture from time to time should be well shaken to make a thoroughly homogeneous solution, and which, when sufficiently heated, is of a syrupy consistency. The mixture in the receptacle after being heated to fully 212 and allowed to rest has a scum upon the top, and, furthermore, additionally, at the bottom of the receptacle a residual deposit of unavoidable foreign matters. Between the scum above and the deposit below is the syrupy mass of the composition, which can be removed from the receptacle through a tap in the side thereof, a little distance above the bottom. Care should be taken in thus separating the liquid not to draw with it the residuum or the scum. The preparation is then transferred into suitable receivers and is there allowed to cool. The same when eool has become a thick viscid body. To this composition is added the coloring-matter or pigment in the proportion of four drams of the coloring-matter to eight drams of the composition. The two are then ground thoroughly together with pestle and mortar and on a slab of plate-glass with a muller, or by other suitable means, and finally the glycerin in small quantity-say three drams, or as much thereof as may be deemed adequate-is added and mixed with the mass should it be needed to retard drying. The product when finished is of the consistency of the paints sold in collapsible tubes. It may be put in tubes of that kind and can be there kept indefinitely. \Vhcn required for use, the tube in which the same is held can have its cap removed and contents then pressed out in the usual way through the neck.

Any suitable coloring-matter can be usedfor example, eosin in case a carmine tint is wanted, green anilin if a green,blue anilin if a blue, and so on.

\Vhen it is attempted to apply a film of gelatin or pyroxylin to a stamp whose stamped design is produced by the use of my composition, the alcohol or ether of the pyroxylin solution or the water of the gelatin solution will at once so affect the composition as to effaee or obliterate the design to such an extent as to render the stamp unavailable for after use. The same is true if it be attempted by steaming or by the application of water to take the stamp from the surface to which it it is adhered. It is also impractical to remove canceling-inarks from such a stamp without effectually and beyond remedy eltacing the design on the latter.

I am aware that salicylic acid has been employed in various compounds as an antiseptic or preservative, and this I do not claim; but I am not aware that it has ever before been combined as an essential ingredient with sugar to form a compound such as and possessing the characteristics hercinbefore described, and this I believe to be new with me.

IIa-ving described my invention and the best way now known to me of carrying the same into elfcct, what I claim herein as new, and desire to secure by Letters Patent, is as follows:

1. A vehicle for pigment or coloring-matter, consisting essentially of sugar and water and salicylic acid, in substantially the proportions specified, the sugar being largely in excess of the water, and the acid being not materially less than three per cent. of the mass, substantially as hereinbefore set forth.

2. A vehicle for pigment or coloring-matter consisting essentially of sugar, gun1-arabie, water and salicylic acid in substantially the proportions specified, the sugar being largely in excess of the waterand gum-arabie and the acid being not materially less than three per cent. of the mass, substantially as hereinbefore set forth.

3. A composition of matter consisting of water, sugar, gum-arabic and salicylic acid in substantially the proportions stated, the sugar being largely in excess of the water and gum-arabic and the salicylic acid being not materially less than three per cent. of the mass, in conjunction with a suitable pigment or coloring-matter, substantially as hereinbefore set forth.

4;. A composition of matter consisting of water, sugar, gum-arabic and salicylic acid taken in the proportions substantially as specified, the sugar being largely in excess of the water and gum-arabic, and the acid being not materially less than three per cent. of the mass, in conjunction with a pigment or coloring-matter, and glycerin, substantially as hereinbefore set forth.

In testimony whereof I al'fix my signature in presence of two witnesses.

FRANCIS ll. IIALL.

'itnesses:

FRANCES D. HALL, CATHERINE DOWLING. 

